During a percutaneous gastrostomy procedure, a gastrointestinal aspirating and feeding tube or other type of catheter is positioned within the gastrointestinal tract of a patient. Initially, the patient's stomach is percutaneously secured to the abdominal wall using "T" or "H"-shaped fasteners inserted into the stomach with a surgical fastener implantation device. Upon successful gastral securement, a thin metal or plastic "J"-wire is percutaneously introduced into the stomach through a hollow needle. If necessary, the distal end of the "J"-wire may be advanced to its required operational position within the gastrointestinal tract using the biopsy forceps of a gastroscope. A hollow dilator/introducer is subsequently displaced along the "J"-wire until it is percutaneously inserted into the patient, perforating the stomach.
Generally, a dilator/introducer is a multiple-piece device comprising a hollow dilator partially and slidably enclosed within an elongated introducer tube. The dilator includes a longitudinally extending interior passageway for receiving the "J"-wire therethrough, and a tapered, acicular end portion for perforating the abdominal and stomach walls of a patient. The elongated introducer is a frangible tube having first and second halves. The introducer includes a first end having an opening that is perpendicular to the longitudinal axis of the tube, and a second open end having a pair of independent wings or ears for longitudinally splitting apart the first and second halves of the frangible tube. When the introducer is mounted over the dilator, the front end of the introducer is disposed proximate the rear of the tapered, acicular end portion of the dilator.
As the dilator is inserted into a patient's tissue, it operates to delicately spread apart (dilate) the tissue surrounding the entry hole formed by the hollow needle during the gastral insertion of the "J"-wire, thereby allowing the relatively large diameter introducer to pass through the entry hole with a minimum degree of resultant tissue trauma or damage.
Although currently available dilator/introducer devices generally provide a minimally acceptable level of performance, the devices exhibit a plethora of deficiencies when utilized during a percutaneous gastrostomy procedure.
One of the most serious problems associated with conventional dilator/introducer devices is the tendency of the first and second halves of the frangible introducer to prematurely split apart as the dilator/introducer is initially inserted into a patient. Depending upon the degree of premature, longitudinal separation, the surgeon may be required to remove the damaged dilator/introducer and reinsert a second, undamaged dilator/introducer into the patient, before continuing with the percutaneous gastrostomy procedure. As should be readily apparent, the reinsertion of a second dilator/introducer may result in additional, unwanted, deleterious tissue damage at the puncture site, potentially increasing the duration of the healing process and/or increasing the risk of postoperative infection.
The dilator utilized in many currently available dilator/introducer devices includes an opening, proximate the pair of wings on the introducer, for receiving the "J"-wire therethrough during a percutaneous gastrostomy procedure. Unfortunately, the location of the "J"-wire prevents the surgeon from securely and comfortably grasping the dilator/introducer device during percutaneous insertion. Further, the surgeon generally cannot apply force directly against the end of the dilator without inadvertently crimping the "J"-wire, rendering it useless. As such, the device must be awkwardly gripped only along its sides during insertion, potentially resulting in a less secure grip, hand slippage or a loss of control during insertion.
U.S. Pat. No. 5,139,486 to Moss, incorporated herein by reference, discloses an improved dilator/introducer device which avoids, at least to a limited degree, the above-described deficiencies associated with the operational orientation of the "J"-wire, by modifying the rearward end of the dilator to facilitate the handling of the dilator/introducer. Specifically, a longitudinal slot is formed through one side of the rearward end of the dilator to allow the "J"-wire to unobtrusively exit from the longitudinally extending central bore of the dilator. As such, a surgeon is able to apply direct pressure against the rear face of the dilator without damaging the "J"-wire. Advantageously, the incorporation of the longitudinal slot improves directional stability and force transfer during the insertion process, and reduces the probability of slippage.
Although the improved dilator/introducer device disclosed in U.S. Pat. No. 5,139,486 to Moss has proven to be a significant step forward in the art, it is deficient in several respects. First, during a percutaneous gastrostomy procedure, the surgeon is required to manually direct the end of the "J"-wire through the longitudinal slot disposed in the rearward end of the dilator. During such a manual manipulation, the surgeon may inadvertently bend the "J"-wire, potentially rendering it unsuitable for the next stage of the percutaneous gastrostomy procedure. Second, the surgeon is required to manually insert an optional plug into the rearward open end of the slotted dilator to not only prevent the "J"-wire from exiting through the rear face of the dilator where it may be damaged, but also to provide an increased surface area at the end of the dilator for the surgeon to push against during the insertion process.